1. Field of the Invention
The present invention relates to a supporting mechanism for a vehicle mounting apparatus (such as a vehicle magazine mounting-type disk apparatus (disk changer)), in which the vehicle mounting apparatus body is resiliently supported by springs in the housing, and, more particularly, to a supporting mechanism for a vehicle mounting apparatus, which stably supports the vehicle mounting apparatus body placed in two different postures so as to be oriented in different directions.
2. Description of the Related Art
The body of a vehicle mounting apparatus is resiliently supported in the housing to prevent vibration of a vehicle body, when exerted on the housing, from being directly exerted on the vehicle mounting apparatus body, in order to allow stable operation of, for example, a disk drive mechanism in the vehicle mounting apparatus body.
FIG. 5 is a schematic view of a magazine-type disk apparatus (disk changer), taken as an example of a vehicle mounting apparatus, as viewed from an end face of the apparatus.
Referring to FIG. 5, a vehicle mounting apparatus body 2 is accommodated in a housing 1. A magazine with a plurality of disks is inserted in direction A into the vehicle mounting apparatus body 2. A disk drive section 3, which moves in the Y directions, is provided in the vehicle mounting apparatus body 2. The disk drive section 3 moves in the Y direction in the vehicle mounting apparatus body 2 to allow selection of any one of the disks in the magazine, and stops in front of the selected disk in the magazine from where the selected disk is drawn out for mounting it to the disk drive section 3 which drives the disk.
The vehicle mounting apparatus body 2 is supported by a plurality of (pulling) springs 4a and 4b in the housing 1. In the conventional example shown in FIG. 5, points connecting the plurality of springs 4a and 4b to the vehicle mounting apparatus body 2 are designated 2a, points connecting the two springs 4a to the housing 1 are designated 1a, and the points connecting the two springs 4b to the housing 1 are designated 1b. More specifically, the end face of the vehicle mounting apparatus body 2 is supported in the housing 1 by the four springs 4a and 4b. The opposite end face of the vehicle mounting apparatus is similarly supported by four springs 4a and 4b.
The four springs are disposed such that two of the springs 4a and 4b and the other two springs 4a and 4b extend vertically so as to be symmetrical to and disposed on opposite sides of an axis Xg passing through the center of gravity G of the vehicle mounting apparatus body 2 of FIG. 5. In FIGS. 5 and 6, the pulling force of the two springs 4a is designated Fa, the force component of the force Fa in the direction of the axis Xg is designated Fa1, and the force component of the force Fa in the direction of axis Yg is designated Fa2. The pulling force of the other two springs 4b is designated Fb, the force component of the force Fb in the direction of the axis Xg is designated Fb1, and the force component of the force Fb in the direction of the axis Yg is designated Fb2.
The disk apparatus can be placed in two postures which are selectable by the user. It can be placed in a first posture in which the axis Yg is oriented in the direction of the center of gravity, as shown in FIG. 5, or in a second posture in which the axis Xg is oriented in the direction of the center of gravity, as shown in FIG. 6.
In the disk apparatuses shown in FIGS. 5 and 6, two of the springs 4a and 4b and the other two springs 4a and 4b are symmetrically disposed to the axis Xg, so that when the disk apparatus is in the first posture of FIG. 5, the force components Fa1 and Fb1 in the horizontal direction are virtually in equilibrium, which is also true for the force components Fa2 and Fb2 in the vertical direction. When the disk apparatus is in the second posture of FIG. 6, the force components Fa2 and Fb2 in the horizontal direction are virtually in equilibrium, which is also true for the force components Fa1 and Fb1 in the vertical direction.
Therefore, it is unnecessary to change the spring extension directions and extension positions, when the user uses the disk apparatus in the first posture of FIG. 5 and in the second posture of FIG. 6.
The supporting mechanisms of the conventional magazine selecting type disk apparatuses of FIGS. 5 and 6 have the following problems:
(1) In the first posture, the vertical force component Fa2 (FIG. 5) of the pulling force of the associated spring 4a connected to the vehicle mounting apparatus body 2 is substantially in equilibrium with the vertical force component Fb2 (FIG. 5) of the pulling force of the associated spring 4b. In the second posture, the vertical force component Fa1 (FIG. 6) of the pulling force of the associated spring 4a connected to the vehicle mounting apparatus body 2 is virtually in equilibrium with the vertical force component Fb1 (FIG. 6) of the pulling force of the associated spring 4b. Therefore, in both of the postures of FIGS. 5 and 6, there is a decrease in the elastic supporting force which opposes the gravitational force to suspend the vehicle mounting apparatus body 2, so that the device body 2 has a greater tendency to fall in the direction of gravitational force. Consequently, when a vibration with a large vertical amplitude is exerted on the housing 1, the vehicle mounting apparatus body 2 tends to hit the bottom surface of the housing 1, and is thus scratched more often.
(2) In the second posture of FIG. 6, the points 2a, 2a connecting the springs 4a and 4b to the vehicle mounting apparatus body 2 are located on the vertical line (or axis Xg) passing through the center of gravity G. Since the supporting points of the springs 4a and 4b to the vehicle mounting apparatus body 2 are located on the vertical line (axis Xg) passing through the center of gravity G, the vehicle mounting apparatus body 2 in the posture of FIG. 6 is unstable in the rotational directions designated .alpha. and .beta. in FIG. 6. Therefore, for example, when the disk drive section 3 moves in the Y directions in the vehicle mounting apparatus body 2 in order to select a disk and the center of gravity of the vehicle mounting apparatus body 2 is shifted either toward the left or right of the axis Xg, the vehicle mounting apparatus body 2 tends to tilt in the direction in which the center of gravity is tilted, either toward the .alpha. or .beta. directions. When the vehicle mounting apparatus body 2 tilts in the housing 1 and an external vibration is exerted on the body 2, the body 2 tends to hit an inner wall of the housing 1. In addition, it becomes difficult to mount the magazine into the vehicle mounting apparatus body 2 in direction A, since the opening of the vehicle mounting apparatus body 2 is tilted.
(3) In the disk apparatuses of FIGS. 5 and 6, the magazine is mounted into the vehicle mounting apparatus body 2 from direction A, with the force component Fa1 being substantially in equilibrium with the force component Fb1 along direction A, so that when the magazine is mounted into the vehicle mounting apparatus body 2 in direction A, the inserting force causes the vehicle mounting apparatus body 2 to move along the axis Xg more easily. This results in poor tactile feel during magazine insertion operations.